Heat system and metabolism measurement method

Abstract

The invention relates to a heat system and a metabolism measurement method, and belongs to the technical field of biomedical engineering. The heat system comprises a metabolism bin, a centrifugal backward fan, a metabolic gas analysis module, a flow meter, a sample pump, a multi-information visual system, a cylinder gas cylinder, a pipeline and display equipment; the metabolic gas analysis module comprises an oxygen analyzer, a carbon dioxide analyzer, a hygrothermograph and a pressure meter; the multi-information visual system comprises a thermal imaging camera, an infrared camera, an infrared light source and a deep learning module; an inlet and an outlet of the metabolism bin are connected through a pipeline, the cylinder gas cylinder is arranged at the inlet, and the flowmeter and the centrifugal backward fan are sequentially connected behind the cylinder gas cylinder; branch pipelines are respectively arranged at an inlet and an outlet of the pipeline and are used for extracting sample gas for analysis. The metabolic mode and the metabolic rate of the subject are evaluated by capturing the amount of oxygen inhaled by the subject and the amount of carbon dioxide exhaled by the subject.

Description

Technical Field

[0001] This invention relates to metabolic research techniques, specifically to a caloric system and a metabolic measurement method, belonging to the field of biomedical engineering technology. Background Technology

[0002] Metabolic research elucidates the mechanisms of energy production and consumption, providing a deeper understanding of how the human body generates and consumes energy. This research has broad scientific and clinical applications, such as using metabolic research findings for health and disease management, personalized medicine, and exercise and fitness optimization, providing crucial theoretical foundations and applied support for multiple fields including medicine, health, exercise, basic science, and public health.

[0003] Indirect calorimetry is an important tool in metabolic research, providing insights into a patient's energy expenditure by measuring oxygen consumption and carbon dioxide production. Traditional large-scale calorimetric systems face challenges such as slow response times, data delays, and distortion. These systems primarily employ push-pull or pull airflow techniques, supplemented by active mixing to promote gas exchange, such as using push-pull ventilation systems to facilitate gas exchange, and typically employing active mixing indoors to accelerate equilibrium. However, these methods require time for the gases to distribute evenly throughout the system and reach equilibrium, often resulting in a prolonged equilibrium time. Therefore, these methods are limited by this extended equilibrium time, making it difficult to achieve a time resolution of less than one minute in large rooms. This leads to data delays and potential distortion, impairing the ability to accurately measure metabolic rates in real time. In other words, actual metabolic changes may not be reflected in the measurement data promptly; furthermore, measurements taken when the gases are not completely mixed may lead to data distortion, failing to accurately reflect the true metabolic state. Summary of the Invention

[0004] To overcome the inherent time resolution limitations of large-capacity chambers in existing metabolic measurement technologies, which prevent accurate reflection of true metabolic conditions, this invention proposes a thermal system and a method for metabolic measurement based on the system.

[0005] To achieve the above objectives, a first aspect of the present invention provides a heat system, comprising:

[0006] Metabolic chamber, centrifugal rear fan;

[0007] Metabolic gas analysis module: includes an oxygen analyzer, a carbon dioxide analyzer, a thermometer / hygrometer, and a pressure gauge; the oxygen analyzer is configured to measure the oxygen content of air samples at the inlet and outlet of the metabolic chamber to assess oxygen consumption during metabolism; the carbon dioxide analyzer is configured to measure the carbon dioxide content of air samples at the inlet and outlet of the metabolic chamber to assess carbon dioxide production during metabolism; the thermometer / hygrometer is configured to measure the temperature and water vapor content at the inlet and outlet of the metabolic chamber, and convert the measurement data into a comparison of oxygen and carbon dioxide concentrations under standard conditions (STP); the pressure gauge is configured to measure the air pressure at the inlet and outlet of the metabolic chamber, and convert the measurement data into a comparison of oxygen and carbon dioxide concentrations under standard conditions.

[0008] Flow meter: installed to measure the gas flow rate at the outlet of the metabolic chamber; the gas at the outlet of the metabolic chamber is a mixture of oxygen and carbon dioxide. By calculating the overall content of oxygen and carbon dioxide at the outlet, the accuracy of the measurement results can be ensured.

[0009] Sample pump: It is set to draw a small amount of air sample from the inlet or outlet of the metabolic chamber for the analytical instrument to detect changes in concentration;

[0010] The multi-information vision system comprises a thermal imaging camera, an infrared camera, an infrared light source, and a deep learning module. The thermal imaging camera monitors the subject's thermal characteristics, which are indirectly related to metabolic activity. Infrared imaging, combined with the deep learning module, allows for tracking of the subject's position and movement. The dual-imaging system within the multi-information vision system enables real-time adjustments to the measurement process, thereby improving the accuracy of the collected data.

[0011] Gas cylinders: provide calibration gas to ensure the accuracy and reliability of analytical instruments;

[0012] Piping: Ensure that the air samples are transported without contamination; stainless steel piping is preferred.

[0013] Display devices: receive, calculate, and display data;

[0014] The gas cylinder is located at the upstream inlet, and a flow meter and a centrifugal backflow fan are connected in sequence thereafter. Branch pipes are opened at the inlet and outlet of the pipeline to extract sample gas for analysis. The branch pipes are connected in sequence to a sample pump, a pressure gauge, a thermometer and hygrometer, a carbon dioxide analyzer and an oxygen analyzer. A small hole is provided at the center above the metabolic chamber for inserting a variable frequency nozzle.

[0015] Preferably, both the thermal imaging camera and the infrared camera are installed in a corner of the metabolic chamber.

[0016] Preferably, it also includes a HEPA filter, which can filter particles such as bacteria larger than 3 micrometers in the airflow, while also reducing turbulence and ensuring the purity of the air sample. The HEPA filter is connected after the centrifugal fan.

[0017] Preferably, the sample also includes a gas condenser to remove water vapor from the gas sample, preventing corrosion of critical instruments and thus ensuring measurement accuracy. The gas condenser is connected between the sample pump and the thermometer / hygrometer.

[0018] A second aspect of the present invention provides a metabolic measurement method, comprising the following steps:

[0019] Information collection: The collected information includes the subject's temperature information T1 and movement information A inside the metabolic chamber, as well as the temperature T2 and humidity at the entrance and exit of the metabolic chamber, the air pressure P1 at the entrance and P2 at the exit, and the temperature information T3 inside the metabolic chamber.

[0020] Gas concentration measurement: Measuring oxygen concentration C O2 and carbon dioxide C CO2 concentration;

[0021] Gas flow rate measurement: Measure the airflow velocity at the outlet of the metabolic chamber;

[0022] Data processing and metabolic rate calculation:

[0023] 1. Deep Learning: Infrared imaging data is input into a deep learning algorithm to output the subject's behavior (such as sleeping, cycling, etc.) and location information;

[0024] 2. Gas volume calculation: Calculate the gas volume by multiplying the concentrations of oxygen and carbon dioxide by the flow rate;

[0025] 3. Volume Correction: The measured data are converted to standard state (STP) gas volume using a gas volume correction formula; the volumes and velocities of oxygen and carbon dioxide flowing into and out of the calorimetric system are corrected to standard gas masses. The equation for calculating this correction factor is as follows:

[0026]

[0027] The correction formula corrects the gas volume at the inlet and outlet in real time to ensure data accuracy.

[0028] 4. Metabolic rate calculation: From the start of operation of the metabolic chamber to its shutdown, gas flow rate * concentration * correction formula = correction result;

[0029] The subject's metabolic rate was calculated based on the corrected gas volume.

[0030] Furthermore, there is a device calibration step before information collection.

[0031] Preferably, calibrating the device through experiments simulating gases includes the following steps:

[0032] Laminar flow state detection: After starting the centrifuge, an airflow for the experiment is generated by the fan; then carbon dioxide smoke is sprayed from different directions to form a visible airflow; a thermal imaging camera is used to capture thermal images of the airflow in real time; observe whether vortices are generated in the airflow through the thermal imaging images. If there are obvious vortices, it means that the airflow is not laminar, otherwise it is laminar. The characteristic of laminar flow is a smooth, orderly, unmixed fluid layer. Since carbon dioxide has different thermal characteristics compared with the surrounding air, laminar flow can be observed by using carbon dioxide gas.

[0033] Human metabolism simulation: A mixture of nitrogen and carbon dioxide in an 8:2 ratio is injected to simulate human metabolism. Simulated gases are used because they are controlled, while the gases breathed by real people are uncontrolled, thus ensuring the controllability and repeatability of the experiment.

[0034] The present invention has the following beneficial effects:

[0035] This invention assesses a subject's metabolic patterns and metabolic rate by capturing the amount of oxygen inhaled and carbon dioxide exhaled. Through experiments simulating gases, the accuracy of sensors and measuring devices is calibrated and verified. Furthermore, the accuracy and reliability of the actual data are ensured by comparing and verifying the actual measurement data with the simulated data obtained in Method 1. Unlike existing metabolic chambers that use suction or push airflow and active gas mixing via fans, this invention integrates a fluid dynamics model to simulate and optimize gas flow within the metabolic chamber. This achieves laminar airflow to minimize gas turbulence and dead zones, ensuring that the subject's exhaled gas reaches the outlet rapidly and remains in the room with minimal residue. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of a heat system structure according to the present invention. The direction of the arrow in the diagram indicates the direction of gas flow. Detailed Implementation

[0037] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0038] like Figure 1 The diagram shown is a schematic of a heat system structure provided by the present invention. The gas cylinder is located at the very top, i.e. Figure 1 The central inlet is connected to the outlet by a pipe, on which a flow meter, a centrifugal backward blower, and a HEPA filter are connected in sequence; the HEPA filter is installed at the air inlet of the metabolic chamber. Figure 1(Not shown), both the thermal imaging camera and the infrared camera are installed in a corner of the metabolic chamber and electrically connected to the information processing center. Branch pipes are installed at the inlet and outlet of the main pipeline for extracting sample gases for analysis. These branch pipes are sequentially connected to a sample pump, a gas condenser, a pressure gauge, a thermometer and hygrometer, a carbon dioxide analyzer, and an oxygen analyzer. A small hole is located at the center of the top of the metabolic chamber for inserting a variable frequency nozzle. Figure 1 (Not shown).

[0039] Laminar flow detection: The centrifugal backward fan is activated. During testing, a variable frequency nozzle is inserted into the metabolic chamber to spray carbon dioxide gas from different directions, creating a visible airflow. A thermal imaging camera captures real-time thermal images of the airflow. The presence of vortices in the airflow is observed. The absence of obvious vortices indicates laminar flow, allowing for the next step of human metabolic simulation. If the airflow is not laminar, the air velocity / flow rate is adjusted until it reaches a laminar flow state.

[0040] Human metabolism simulation: Injecting a mixture of nitrogen and carbon dioxide in an 8:2 ratio.

[0041] After passing through the aforementioned human metabolic simulation and correction equipment, the subject enters the metabolic chamber to begin monitoring and information collection.

[0042] Information Acquisition: Thermal imaging cameras collect the subject's body temperature and the temperature inside the metabolic chamber; infrared cameras collect the subject's movement information, which serves as input for a deep learning algorithm, which can employ existing technologies such as RITnet; an oxygen analyzer measures the oxygen concentration at the inlet and outlet of the metabolic chamber; a carbon dioxide analyzer measures the carbon dioxide concentration at the inlet and outlet of the metabolic chamber; a thermometer and hygrometer measure the temperature and humidity at the inlet and outlet of the metabolic chamber; a pressure gauge measures the air pressure at the inlet and outlet of the metabolic chamber; and a flow meter measures the airflow velocity at the outlet of the metabolic chamber.

[0043] The thermometer and hygrometer, along with the pressure gauge, are used to convert the measured data into a comparison of oxygen and carbon dioxide concentrations under Standard Temperature and Pressure (STP) conditions. The oxygen and carbon dioxide concentration values ​​obtained under the actual measurement environment reflect the gas concentrations under the current temperature, humidity, and pressure conditions, but these values ​​are dynamic and change with environmental conditions. The other instrument converts the measured gas concentration data into values ​​under Standard Temperature and Pressure (STP) conditions, which are standardized values ​​used to eliminate the influence of environmental conditions and allow for a unified comparison of different measurement results.

[0044] Data processing and metabolic rate calculation:

[0045] (1) Input the imaging data of the infrared camera into the deep learning algorithm and output the subject's behavior (such as sleeping, cycling, etc.) and location information;

[0046] (2) Gas volume calculation: The gas volume is calculated by multiplying the concentrations of oxygen and carbon dioxide by the flow rate;

[0047] (3) Volume Correction: The measured data are converted to standard state (STP) using the gas volume correction formula.

[0048] The gas volume is measured below; the correction formula corrects the gas volume at the inlet and outlet in real time to ensure data accuracy.

[0049] The volumes and velocities of oxygen and carbon dioxide flowing into and out of the heat system are corrected to standard gas masses. The equation for calculating this correction factor is as follows.

[0050]

[0051] (4) Metabolic rate calculation: From the start of the metabolic chamber to the stop of operation, gas flow rate * concentration * correction formula = correction result;

[0052] The subject's metabolic rate was calculated based on the corrected gas volume.

Claims

1. A heat system characterized by, The heat system comprises a metabolic chamber, a centrifugal backward fan, a metabolic gas analysis module, a flow meter, a sample pump, a multi-information visual system, a cylinder gas bottle, a pipeline and a display device; wherein the metabolic gas analysis module comprises an oxygen analyzer, a carbon dioxide analyzer, a temperature and humidity meter and a pressure gauge; the multi-information visual system comprises a thermal imaging camera, an infrared camera, an infrared light source and a deep learning module; the inlet and outlet of the metabolic chamber are connected by pipelines, the cylinder gas bottle is arranged at the inlet, and the flow meter and the centrifugal backward fan are sequentially connected after the cylinder gas bottle; branch pipelines are arranged at the inlet and the outlet of the pipeline respectively for extracting sample gas for analysis, wherein the branch pipelines are sequentially connected with the sample pump, the pressure gauge, the temperature and humidity meter, the carbon dioxide analyzer and the oxygen analyzer; a small hole is arranged at the top center of the metabolic chamber for inserting a variable frequency nozzle. The heat system further comprises a HEPA filter screen connected after the centrifugal backward fan.

2. The heat system of claim 1, wherein, The heat system further comprises a gas condenser connected between the sample pump and the temperature and humidity meter.

3. The heat system of claim 1, wherein, The method comprises the following steps, 4. A method of measuring metabolism, characterized by: information collection: the collected information includes temperature information T1 of the subject in the metabolic chamber, action information A, and temperature T2 and humidity at the inlet and outlet of the metabolic chamber, gas pressure P1 at the inlet of the metabolic chamber and gas pressure P2 at the outlet, temperature information T3 in the metabolic chamber; gas flow rate measurement: measuring the gas flow rate at the outlet of the metabolic chamber; Gas concentration measurement: Measurement of oxygen concentration C O2 and carbon dioxide C CO2 concentration; data processing and metabolic rate calculation: (1) deep learning: using infrared imaging data to input deep learning algorithm to output the behavior (such as sleeping, cycling, etc.) and position information of the subject; (2) gas volume calculation: the concentration of oxygen and carbon dioxide is multiplied by the flow rate to calculate the gas volume; (3) volume correction: using the gas volume correction formula to convert the measured data into the gas volume under standard state; (4) metabolic rate calculation: from the start of the metabolic chamber to the stop of the operation, the gas flow rate * concentration * correction formula = correction result; according to the corrected gas volume, the metabolic rate of the subject is calculated. Before information collection, there is a device correction step.

5. The metabolic measurement method according to claim 4, characterized by: The device correction step comprises:

6. The metabolic measurement method of claim 5, wherein: laminar flow state detection: starting the centrifugal backward fan to generate gas flow for the experiment; then injecting carbon dioxide smoke from different directions to form visualized gas flow; using a thermal imaging camera to capture thermal imaging images of the gas flow in real time; observing whether vortexes are generated in the gas flow through the thermal imaging images, if there are obvious vortexes, it indicates that the gas flow is not laminar, otherwise it is laminar; human metabolism simulation: injecting 8:2 ratio of nitrogen and carbon dioxide mixed gas to simulate human metabolism. ​

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